A plastic shopping bag weighs about 5 grams. Plastic product packaging does not weigh 1kg, not even close.

Second, the shape does matter. Bags are especially bad because they are large, thin and soft, they're easier to be carried away by wind or water, and easier for animals to get tangled in or mistaken for food.

Agreed they have to be reined in. But on the recycling side, they are spectacularly inefficient. They are bulky to recycle - they never lay down flat again. The entire semi trailer load at my recycle center probably weighs a couple hundred pounds of plastic, mostly air. They are very, very cheap to make and lots of trouble to recycle - its arguable the recycle cost is greater than the environmental cost of a new one.

No, do not read CO2. That's not what banning plastic bags is about. It's about not having them all over the environment where all kinds of animals, from sea turtles to cows to elephants, eat them or get entangled in them

I spent an hour or so researching the issue a long time ago and I seem to recall another study by a French supermarket chain. You need to reuse your cotton bags a lot -- hundreds of times is right -- for it to become worthwhile. Which is doable, of course.

And of course, the carbon footprint of both plastic bags as well as cotton bags varies wildly depending on the weight etc.

How about I use a plastic bag twice? Now you have to use the canvas one 400 times.

Its just a losing gambit. You know how many shopping bags we have around the house? Supposed to save energy, but once you have 4 or 5 of them, you're up to a lifetime supply of plastic bags. And I'm sure we're not the only once.

You don’t have to use the canvas one 200 times. It’s more like 130. And less if you use nylon or hemp or anything less energy costly than cotton. But yeah, if you want to reuse your throwaway bags, go ahead. It’s certainly a greener option than throwing them out.

It’s not “eco-theater” to want to reduce the ecological cost of bags, though. Not is it “eco-theater” to want to keep millions of plastic bags out of the oceans and rivers, or out of storm drains where they cause clogs, or out of bushes and trees where they are just ugly.

By that metric, what is the environment and why is it important to protect it? On an abstract enough scale, we and our plastic are simply evolutionary products and the fact that we are wiping out species and cataclysmically heating the planet is just a geological event that might be called The Great Human Extinction by some distant inteligent race.

Keeping the planet livable and diverse is no more objective than keeping it plastic free. Ecology is by definition a human value, the universe doesn't care about CO2, biodiversity or erosion anymore than it cares about plastic bags.

(But sure, subjectively, plastic bags are a lesser concern, because they merely inconvenience us and trigger our empathy when a critter chokes on them, without directly threatening our own survival).

Yes, and the cute furry animals get all the protection too. But its nonsense, if avoiding environmental meltdown is your goal. If its about feeling good about yourself when you throw that pop can in the recycle bin, that's theatre.

If you read more closely, you'll find out that this already is my argument.

But I'd take it even further because even that is BS theater: industrial production of tons of crap in general should slow down. The packaging is an insignificant part of it. It just makes for nice headlines because dolphins and co get caught in it.

- Plastics really don't mix well. Even trace amount of a different polymer (those numbers in the bottom) will destroy the strength of a batch of plastic (there is research in this though)
- Recycling is expensive and in an economic battle against new stock (carbon tax?).

Cleaving the bonds to make diesel or feedstock is another option to "recycle" polymers (I dunno why it's not done. energy intensive wrt to oil? Dirty?)

Plastics are amazing... but we really should stop using them altogether except for fringe no alternative cases.

P.S. turns out plastics are bio-degradable by some tough organisms. So there's hope.

Most plastics labelled "biodegradeable" aren't actually what they say. What they do is break down under ultraviolet light into very tiny particles you can't see but which are still plastic. These diffuse into the environment, but they never truly break down into more natural compounds.

It's the equivalent of sweeping all those bags under the rug. They're still out there, just permeating into everything instead of being visible.